Managing waste represents a challenge. In most of the world, including North America, the consumer does one of two things with ordinary garbage: burn it or bury it. Neither one is a good option for the environment. Burning garbage in incinerators releases dangerous gases and dust (particulate matter) that contribute to global warming and releases environmental pollutants (toxins) into lakes, forests, oceans and cities located half a world away from their source of origin. Most incinerators in industrialized countries remove large quantities of particles and pollutants, thus ensuring somewhat cleaner air. But the bulk of what these systems remove ends up in a landfill. Landfills do not represent an environmentally friendly solution for numerous reasons. Landfills are the source of toxins, leachate and greenhouse gases. Burying garbage also causes both air and water pollution, and simply transporting garbage to the landfills consumes an increasing amount of fossil fuels that produce more pollution and other problems.